The broad goals of this proposal are to increase understanding of how surface properties are represented by the visual system. In particular, the project seeks to deepen our understanding of perceptual constancies, the means by which objects and surfaces maintain their appearance in changing contexts. This kind of research falls under the NEI's stated mission of understanding visual function.
The first aim of the proposal is to study the visual cues that are important in understanding how scenes affect the perception of surface lightness. In particular, the aim will use psychophysical methods to study the image features that the visual system uses to discount the effects of shadows, illumination changes, and transparency in recovering surface lightness.
The second aim will build on the findings of the first;it will seek to identify regions in human visual cortex that respond as the interpretation of shadows and transparencies vary, influencing perceived surface lightness.
The third aim will examine the effects of scene interpretation on the representation of the size of surfaces and objects. In this aim, we will study how perceived depth influences the perceived size of objects, and how size constancy mechanisms are represented in visual cortex.

Public Health Relevance

Basic mechanisms of visual processing are impaired in a wide range of disabilities including psychiatric conditions such as schizophrenia and autism. One impairment found in a number of conditions is an abnormal effect of context on visual processing. Understanding how the normal visual system processes information and takes into account contextual information may guide development of tests for early diagnosis of such conditions.

Agency
National Institute of Health (NIH)
Institute
National Eye Institute (NEI)
Type
Postdoctoral Individual National Research Service Award (F32)
Project #
5F32EY019224-03
Application #
7915330
Study Section
Special Emphasis Panel (ZRG1-F02B-B (20))
Program Officer
Steinmetz, Michael A
Project Start
2008-09-01
Project End
2011-08-31
Budget Start
2010-09-01
Budget End
2011-08-31
Support Year
3
Fiscal Year
2010
Total Cost
$52,154
Indirect Cost
Name
Stanford University
Department
Psychology
Type
Schools of Arts and Sciences
DUNS #
009214214
City
Stanford
State
CA
Country
United States
Zip Code
94305
Nune, George; Winawer, Jonathan; Rauschecker, Andreas M et al. (2011) Problem of signal contamination in interhemispheric dual-sided subdural electrodes. Epilepsia 52:e176-80
Wandell, Brian A; Winawer, Jonathan (2011) Imaging retinotopic maps in the human brain. Vision Res 51:718-37
Winawer, Jonathan; Horiguchi, Hiroshi; Sayres, Rory A et al. (2010) Mapping hV4 and ventral occipital cortex: the venous eclipse. J Vis 10:1
Levin, Netta; Dumoulin, Serge O; Winawer, Jonathan et al. (2010) Cortical maps and white matter tracts following long period of visual deprivation and retinal image restoration. Neuron 65:21-31